arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1503.03871cond-mat.str-elcond-mat.stat-mech
收藏

海森堡自旋1/2阶梯的热传导:从弱到强的可积性破缺

Heat conductivity of the Heisenberg spin-1/2 ladder: From weak to strong breaking of integrability

Robin Steinigeweg, Jacek Herbrych, Xenophon Zotos, Wolfram Brenig

摘要:

在线性响应的框架下,利用几种数值方法和微扰理论研究了海森堡自旋1/2阶梯在有限温度下的热导率$κ$,覆盖了整个链间耦合$J_\perp$的范围.我们揭示了一个微扰预测$κ\propto J_\perp^{-2}$,基于简单的黄金法则参数和有效的严格限制$J_\perp \to 0$,适用于一个非常广泛的$J_\perp$,定性和定量。在大的$J_\perp$限制,我们显示幂律缩放相反的性质,即$κ\propto J_\perp^2$。此外,我们证明了弱耦合和强耦合制度连接的一个广泛的最小值,略低于各向同性点在$J_\perp = J_\parallel$。作为温度$T$的函数,该最小值在交换耦合常数的量级上按$κ\propto T^{-2}$到$T$的比例缩放。这些结果提供了一个全面的图片$κ(J_\perp,T)$的自旋梯。

英文摘要:

We investigate the heat conductivity $κ$ of the Heisenberg spin-1/2 ladder at finite temperature covering the entire range of inter-chain coupling $J_\perp$, by using several numerical methods and perturbation theory within the framework of linear response. We unveil that a perturbative prediction $κ\propto J_\perp^{-2}$, based on simple golden-rule arguments and valid in the strict limit $J_\perp \to 0$, applies to a remarkably wide range of $J_\perp$, qualitatively and quantitatively. In the large $J_\perp$-limit, we show power-law scaling of opposite nature, namely, $κ\propto J_\perp^2$. Moreover, we demonstrate the weak and strong coupling regimes to be connected by a broad minimum, slightly below the isotropic point at $J_\perp = J_\parallel$. As a function of temperature $T$, this minimum scales as $κ\propto T^{-2}$ down to $T$ on the order of the exchange coupling constant. These results provide for a comprehensive picture of $κ(J_\perp,T)$ of spin ladders.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑